"It seems to me that if geese are tamed from childhood, they could become pretty good pets and not show aggression to the owner."

I have never known this to be the case. Geese have also attacked my children, the younger the more violent the attack. They neither understand threats, even when I grasped the offending gander by the neck and demonstrated I could easily kill it, it did not relent nipping at my son. I appreciate they are very loving mates, monogamous for life, but they are not safe around young children, and annoying even for adults when they nip.

OTOH, their violent nature is what makes them valuable (besides their meat and eggs), because they guard lesser birds from lesser predators, like rats or crows, who seem just as anxious to avoid being nipped by geese as toddlers.

Thanks!